Question

A researcher wishes to determine whether the rate of waterflow
(in liters per second) over an experimental soil bed can beused to
predict the amount of soil washed away (in kilograms).
Theresearcher measures the amount of soil washed away for various
flowrates, and from these data calculates the least-squares
regressionline to be

amount of eroded soil = 0.4 + 1.3 × (flow rate)

One of the flow rates used by the researcher was 0.3 liters
persecond and for this flow rate the amount of eroded soil was
0.8kilograms (kg). These values were used in the calculation of
theleast-squares regression line. What is the residual
correspondingto these values?